1. Field of the Invention
The present invention relates to novel thioether derivatives, the production method and use thereof, and relates especially to the S containing dendrimers and the synthetic intermediates thereof.
2. Description of the Prior Art
The dendritic molecules, having a unique macromolecular structure, are expected to have a wide field of application. The dendritic molecules which have a unique chemical structure composed of a central core (nucleus), and a branch structure constructed with branches (units) repeated regularly and the surface functional groups, both extending three-dimensionally, have been investigated actively in the field, for example, of nano science, communication science, electro-material science, medical science, pharmaceutical science, biological science, surface science and material science, and so on (References: xe2x80x9cDendritic Moleculesxe2x80x9d, VCH Publication Co. 1996; xe2x80x9cMolecular Design of Dendrimersxe2x80x9d and xe2x80x9cMiscellaneous Functions of Dendrimersxe2x80x9d Gendai Kagaku, June, 1998, on pp. 20-40; xe2x80x9cApplications of Dendrimers as Non-linear Optical Materialsxe2x80x9d in Kobunshi, Vol.47, November, 1998.) It may safely be said, however, that the dendrimer science is xe2x80x9cone of the latest sciencesxe2x80x9d, because it has been highlighted only since about the middle of the year 1990 and the number of the research on it has increased recently.
As for the use of the dendritic molecules, there have been offered a variety of inventions on the subject of industrial use thereof, for example, their use in medicine and agricultural chemicals (JP-A Hei7-330631), use in solar cell and photosensitive material for electrophotography (JP-A Hei11-40871), use in electronic material (JP-A Hei11-171812), use in liquid crystal (JP-A 2000-264965), use in paint and ink (JP-A Hei11-140180), use in fluorescent resin sheet (JP-A Hei11-323324), use in qualitative and quantitative analyses (JP-A Hei11-218494), use in biological response modifier (JP-C Hei8-510761), and so on.
The object of the present invention is to provide both novel dendritic molecules with useful functions and novel synthetic intermediates for producing them.
More specifically, the main object of the present invention is to provide novel dendrimers which are useful as electronic material (for example, as the switch of memory) due to their ability to emit light from the core by transferring electron which exists in the branch structure into the core which has been made electron deficient by absorbing light or electric energy.
Other objects of the present invention will become clear through the explanation hereinafter.
The present inventors made an intensive investigation on the aforementioned problems and succeeded in creating the S atom containing dendrimers of the present invention.
In addition, the present inventors have obtained a lot of novel knowledge about the dendrimers of the present invention which have many sulfur atom in their branch structures. Namely, in the case of the sulfur atom we can make use of their d-orbital electrons which do not exist in the oxygen atom. As the d-orbital electrons of the sulfur atom are placed farther apart from the nuclei than the p-orbital electrons of the oxygen atom, the electrons of the sulfur atom can move more freely than the electrons of the oxygen atom; the light or electric energy can be transferred to the core, which is in an electron-deficient state, with ease; it becomes possible to make the core emit light by constructing the core from a residue of a luminescent compound; and a larger polarization between the branch structure and the core can be obtained with the sulfur atoms than with the oxygen atoms. Consequently, the present inventors have got the knowledge that the dendrimers of the present invention are useful as an electronic material, for example, as the switch of memory.
In addition, the present inventors have found that, although S atom-containing dendrimers can suffer deterioration due to oxidation, it is possible to make them more durable and of a long life by placing substituents with steric bulkiness, preferably t-butyl groups, on the outside of the branch structure, namely, at the opposite end across the branch structure from the core.
Furthermore, the present inventors have found that the S atom-containing dendrimers of the present invention can be produced conveniently and industrially advantageously from a series of novel synthetic intermediates of specific structures.
Based on a lot of novel knowledge mentioned above, the present inventors have carried out an intensive investigation on the subject and completed the present invention.
That is to say, the present invention relates to the compounds and salts thereof:
[1] A dendritic molecule characterized in that it comprises or preferably has a core, a branch structure composed of Unit 1 represented by the following structure, 
, wherein ring A stands for a homo- or heterocyclic six-membered ring, and surface functional groups as the essential constituents.
[2] A dendritic molecule characterized in that it comprises or preferably has a core, a branch structure composed of both Unit 1 described in [1] and Unit 2 represented by the following structure, 
, wherein ring A stands for a homo- or heterocyclic six-membered ring, and/or Unit 3 represented by the following structure, 
, wherein ring A stands for a homo- or heterocyclic six-membered ring, and the surface functional groups.
[3] A dendritic molecule characterized in that it comprises or preferably has a core, a branch structure composed of two or more of the partial branch structures of Unit 1 described in [1], Unit 2 described in [2], and Unit 3 in [2], and the surface functional groups.
[4] A dendritic molecule of any of [1] and [2], wherein the branch structure is of 2-10 generations and is constructed with both a generation or generations of the branch structure composed of Unit 1 described in [1] and a generation or generations of the branch structure Unit 2 described in [2] and/or Unit 3 described in [2].
[5] A dendritic molecule of [1] to [4], wherein the ring A of Unit 1, Unit 2 and Unit 3 is a benzene ring, a pyrimidine ring or a triazine ring.
[6] A dendritic molecule of [1] to [5], wherein the surface functional group is an alkyl group which may be substituted, an aralkyl group which may be substituted, an alkoxy group, an alkoxycarbonyl group or a quaternary ammonium group.
[7] A dendritic molecule of [6], wherein the surface functional group is a t-butyl group.
[8] A dendritic molecule of [1] to [7], wherein the core is a color developing functional group.
[9] A dendritic molecule of [1] to [7], wherein the core is a rhodamine pigment, a quinazoline, a perylene, an azo-compound, 2,5-dihydroxybenzoic acid methyl ester, a porphyrin, 4,4xe2x80x2-dihydroxybiphenyl or 1-(4.4xe2x80x2,4xe2x80x3-trihydroxyphenyl)ethane residue.
[10] A thio-compound represented by the following structure, 
wherein ring A is a ring represented by Formula 5, 
which has each of the substituent B, substituent C and substituent D at the positions denoted with a bond, and may be substituted at the positions where no bond is attached;
substituent B stands for xe2x80x94S(O)nR1,
wherein n stands for an integer of 0-2, and R1 stands for a substituent;
substituent C stands for xe2x80x94X1R2,
wherein X1 stands for a intervening group, and R2 stands for a substituent; and
substituent D stands for a substituent bonded to the ring A through a carbon atom.
[11] A thio-compound of [10], wherein R1 and R2 are, each being the same or different, an alkali metal, a hydrogen atom, an alkyl group which may be substituted, an aralkyl group, a carbamoyl group or a thiocarbamoyl group.
[12] A thio-compound of [10] or [11], wherein X1 is a methylene group, a dimethylmethylene group, an oxygen atom, a sulfur atom, a sulfinyl group or a sulfonyl group.
[13] A thio-compound of any one of [10] to [12], wherein the subtituent D is a cyano group, a formyl group or X2R3, wherein X2 stands for a methylene group which may be substituted, a carbonyl group or a thiocarbonyl group, and R3 stands for a hydroxyl group which may be protected, a mercapto group or an amino group, with the proviso that when X2 is a carbonyl group, then R3 is not a hydroxyl.
[14] 3,5-dimercaptobenzyl alcohol.
[15] 3,5-dimercaptobenzyl mercaptan.
[16] A compound represented by the following structure and a salt thereof, 
wherein each of R1 and R2 stands for
(1) an alkali metal such as sodium and potassium and so on,
(2) a hydrogen atom,
(3) an alkyl group which may be substituted with a fluorine atom, a chlorine atom, a bromine atom, an alkoxy group or a thioalkoxy group, and so on,
(4) a phenyl group which may be substituted with the aforementioned substituent or substituents, or
(5) an aralkyl group which may be substituted with the aforementioned substituent or substituents,
(6) a disubstituted carbamoyl or thiocarbamoyl group represented by the following structure, 
xe2x80x83wherein R7 stands for
(1) an alkyl group which may be substituted with a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom,
(2) a phenyl group which may be substituted with aforementioned substituent or substituents, or
(3) an aralkyl group which may be substituted with aforementioned substituent or substituents,
Z stands for an oxygen atom or a sulfur atom,
n stands for an integer of 0 to 2,
X stands for a methylene group, a dimethylmethylene group, an oxygen atom, a sulfur atom, a sulfinyl group or a sulfonyl group,
Each of R3 and R4 stands for (1) a hydrogen atom, (2) an alkyl group which may be substituted with a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom, and so on, (3) a phenyl group which may be substituted with aforementioned substituent or substituents, or (4) an aralkyl group which may be substituted with aforementioned substituent or substituents, or R3 and R4 may be combined to form a methylene group, a keto group or a thioketo group, or R3, R4 and R5 taken together with the carbon atom to which they are attached may form a cyano group,
R stands for (1) a hydroxyl group, (2) a mercapto group, (3) an amino group, (4) a formyl group, (5) an alkyl group which may be substituted with a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and so on, (6) an alkoxy group which may be substituted with aforementioned substituent or substituents, (7) a thioalkoxy group which may be substituted with aforementioned substituent or substituents, (8) a phenyl group which may be substituted with aforementioned substituent or substituents, (9) an aralkyl group which may be substituted with aforementioned substituent or substituents,
R6 means a hydroxyl group, an alkyl group, an alkoxy group, an alkylthio group, a nitro group, a cyano group, a dimethylamino group, or a diethylammino group.